I know there is only POC coding going on with Yii. I was busy with that same exercise. Any change of either releasing what you have, or providing an indication of which areas are being tackled so that others can be involved here in providing feedback about challenges in porting frameworks without overlap of effort.

Out of curiosity (since we are also looking at PHP frameworks for another project), what was the real objection to Cake? Was it performance? What was the "last straw" that made the LS team ditch Cake?

There were some reasons. The most important issues were related to the fact that CakePHP is a not so flexible framework so at some cases you have to stick to their standards and can't work around it even if there are better solutions.

I think there have also been some problems with the support for different DBs and if I remember correctly, nobody really cared about the bugs we reported to the cake team.

This is an extract from: http://www.gnu.org/licenses/gpl-faq.html#OrigBSD
Why is the original BSD license incompatible with the GPL? (#OrigBSD)
Because it imposes a specific requirement that is not in the GPL; namely, the requirement on advertisements of the program. Section 6 of GPLv2 states:

You may not impose any further restrictions on the recipients' exercise of the rights granted herein.

GPLv3 says something similar in section 10. The advertising clause provides just such a further restriction, and thus is GPL-incompatible.

The revised BSD license does not have the advertising clause, which eliminates the problem.